Solved

usort() function producing bad results on a linux environment, ok on windows

Posted on 2009-07-08
4
277 Views
Last Modified: 2012-05-07
This is really weird, the same code works on windows, but not on linux.

When I run the code below on a windows machine with PHP 5.2.5, it works perfect, I get the output array alphabetically ordered.

When I run it on a linux box running PHP 5.1.6 I get an array that doesn't have the same order as the original array, but it is also not properly sorted.

Do you guys know what part of my code is "environment dependant"? I can hardly believe the same code will produce two different results in different platforms...


// The code here:
 
class TestTwo{
 
                      // This is just the contructor / driver:
	function TestTwo(){
 
                                          // bootstrapping the input array:
		$sort_array = file_get_contents('test_array_sort.txt');
		$attributes_array = unserialize($sort_array);
 
		$this->attributes_array_sorted = $this->createAttributesArraySorted($attributes_array);			
                                          // At this point, I get the right output on Windows, and the badly sorted array in Linux
	}
	
	private function createAttributesArraySorted($attributes_array_){
		
		foreach($attributes_array_ as &$val){
 
			usort($val['children_nodes'], 'TestTwo::cpm_node');
 
		}
		return $attributes_array_;
		
	} /* end private function createAttributesArraySorted($attributes_array_) */
	
    /*
     * Auxiliary function used to sort attributes in alphabetical order 
     */
    static function cpm_node($a,$b){
    	
    	return strcasecmp($a['node_name'], $b['node_name']);
 
    } /* end static function cpm_nodes() */
    
} /* end class TestTwo */

Open in new window

0
Comment
Question by:cabrera48
  • 2
  • 2
4 Comments
 

Author Comment

by:cabrera48
ID: 24809757
A bit more of information: it looks like the cpm_node() function never gets called on linux.

I put a print statement inside of it, and I can see the print output on windows, on linux it doesn't display.

So the problem seem to be in this line:

usort($val['children_nodes'], 'TestTwo::cpm_node');
 
Why would that fail to call TestTwo::cpm_node static function on linux?
0
 
LVL 27

Accepted Solution

by:
ddrudik earned 500 total points
ID: 24814811
See the comments on static method calls/versions here:
http://us3.php.net/manual/en/language.pseudo-types.php#language.types.callback
appears that you are using a version prior to 5.2.3:
array('TestTwo', 'cpm_node')

Although I didn't test the above.
0
 

Author Comment

by:cabrera48
ID: 24815390
You are right, that was the problem, nothing to do with linux, but the PHP version I was using there.

Thank you.
0
 
LVL 27

Expert Comment

by:ddrudik
ID: 24816396
Thanks for the question and the points.
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Build an array called $myWeek which will hold the array elements Today, Yesterday and then builds up the rest of the week by the name of the day going back 1 week.   (CODE) (CODE) Then you just need to pass your date to the function. If i…
These days socially coordinated efforts have turned into a critical requirement for enterprises.
Learn how to match and substitute tagged data using PHP regular expressions. Demonstrated on Windows 7, but also applies to other operating systems. Demonstrated technique applies to PHP (all versions) and Firefox, but very similar techniques will w…
The viewer will learn how to dynamically set the form action using jQuery.

856 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question